- Tag results for Roger Federer
According to the ATP, Federer has to win a record 10th Halle crown if he is to enter Wimbledon on the top world ranking.
Nishikori, a former top 10 regular now ranked 27th after wrist injuries last season, was joined in the second round by fourth seeded Spaniard Roberto Bautista Agut.
Roger Federer overtook Rafael Nadal as world number one with a 6-4, 7-6(3) victory over Milos Raonic in Stuttgart Open.
The Swiss great, who is assured of reclaiming the No. 1 ranking from Rafael Nadal on Monday, broke at 1-1 in the opening set and held his nerve in the second, where Raonic double-faulted.
Roger Federer staged a comeback over Nick Kyrgios to reach the Stuttgart Cup final and take back the world number one ranking.
Federer made sure of returning to the world number one ranking when he beat Kyrgios to reach the final of the Stuttgart Cup.
Milos Raonic hammered 19 aces to eliminate defending champion Lucas Pouille 6-4, 7-6 (7/3) and reach the final at the Stuttgart Cup.
Roger Federer won his 19th match from 21 played this season as his Wimbledon buildup continues on track.
Federer two shook off the rust against Mischa Zverev after a poor start, breaking twice in the second and third sets to earn victory in 93 minutes.
Nadal said he needs to see how his body recovers after a long clay court campaign culminated in an 11th French Open title.
Federer is beginning his grass season in Stuttgart for the third consecutive year after reaching the 2016 semi-finals where he lost to Thiem.
Rafael Nadal's victory on Sunday meant that the last seven Slams have been shared between players who are 30 and over.
Rafael Nadal is 100 points ahead of Roger Federer going into the grasscourt season where the Swiss will be looking to close the gap.
The Spaniard remains philosophical about the rest of his career which has so far yielded 17 majors, 79 titles in total as well as more than USD 100 million in prize money.
Rafael Nadal won his 11th French Open title on Sunday when he defeated Dominic Thiem in the final.